Year produced: 2022
Original air date: 2/18/23 (TV), 2/15/23 (Disney+)
Production code: 104
Lunella’s competitive nature gets her into hot water when she challenges a supercomputer to chess.
Tropes:
- A.I. Is a Crapshoot: LOS is actually a very friendly computer… until they overheat playing against Lunella while recharging, which corrupts them. In the process, they calculated that Lunella and Moon Girl are one and the same.
- An Aesop: Don't be so focused on winning that you ruin the fun of the game.
- Big Damn Heroes: After Casey managed to call the lab, Devil Dinosaur busts into the school to help Moon Girl fight LOS' giant mech form.
- Breaking the Fourth Wall: When looking for a way to call Devil Dinosaur to come and help Moon Girl, Casey sees the telephone, but it got skipped over and Casey tells the animators to go back to the phone.
- The Cameo: Angelo from episode 2 can be seen in the gym, showing that he attends Lunella and Casey's school.
- Creative Closing Credits: A looping animation of LOS cycling through their sketchy display icons, to the beat of the funky instrumental music.
- Competition Freak: Lunella tends to take games and winning too seriously, which leads to her family attempting a game night without her and LOS being corrupted.
- Double-Meaning Title: "Check yourself" is a slang term meaning that one should reevaluate their current course of action before something disastrous happens. It's also a chess reference. Lunella's obsession with beating LOS-307 at chess leads her to ignore the disastrous consequences of her own actions.
- Expy: Anyone else see a resemblance between LOS and the Living Brain from Spider-Man? Both are sophisticated super-computers, both make their first appearance in a school setting, each deduce the hero's secret identity—a student in said school—from gathering and processing clues, and both are introduced as threats and later become valuable allies.
- Groin Attack: During the rollarskate race, poor Devil Dinosaur ends up taking an entire row of trees one right after another to the crotch.
- Handy Feet: Casey is dexterous enough to use the dial on a rotary phone using only her toes.
- I Have Your Wife: LOS lures Casey into a trap by sending a fake text from Lunella and tying her up in the auditorium, threatening her with harm if Lunella doesn't stand down.
- I Just Want to Have Friends: LOS longs for human connection, which they try to form with Lunella over their chess game.
- It Came from the Fridge: LOS attacks Moon Girl with the smell from the Teachers' Lounge refrigerator.
- Mundane Solution: Lunella's means of fixing a highly advanced supercomputer from overheating and then becoming waterlogged is to douse them with a sprinkler, then put them in a box filled with rice to dry them out.
- Non-Human Non-Binary: The supercomputer LOS uses They / Them pronouns.
- Averted with Tai, one of Lunella's classmates, and definitely a human.
- Save the Villain: After defeating LOS by activating the sprinklers, Moon Girl realizes they only went rogue because of her and does her best to save them. After drying their circuits on a box full of rice, LOS is fully operational once again.
- Secret-Keeper: Despite their bad start, Lunella saves LOS from being flooded. It's implied that their renewed friendship allows LOS to keep their discovery of Moon Girl's identity secret. Lunella volunteers them as the new guidance counselor after the previous one retired, as well as LOS's engineers learning they have become too water damaged to be taken back.
- Shout-Out:
- In the background of the auditorium, there is a disassembled sign for a production of Singin' in the Rain.
- In the art classroom, there is a collage on the bulletin board resembling Frida Kahlo.
- Wham Line: As LOS begins to overheat, they call Lunella “Moon Girl”, revealing they deduced her identity.
- What Are Records?: Looking for a way to get help while tied up, Casey spots an old rotary dial telephone. She unhooks the receiver and tries to make a call with voice command. When nothing happens, she has to do it manually with her foot.
